南麂列岛海域春秋季网采浮游植物群落结构特征

Community Structure of Phytoplankton Sampled by Nets in Nanji Islands Sea Area in Spring and Autumn

【目的】研究浙江南麂列岛海洋自然保护区浮游植物群落结构特征及其与环境的关系,为评价该海域生态环境质量的现状及其变化趋势提供科学依据。【方法】以2013年11月和2014年5月对该保护区28个站位的调查数据为基础,分析浮游植物的种类组成,以及细胞丰度、优势度指数、多样性指数、综合富营养化指数等。【结果】南麂列岛多数水体处于富营养状态。春季调查共发现浮游植物2门24种(属),秋季调查共发现浮游植物2门22种(属);物种组成以广温性近岸种为主,主要优势种为甲藻和硅藻。春季调查中夜光藻(Noctilucas cintillans)、圆筛藻属(Coscinodiscus sp.)和海链藻属(Thalassiosirasp.)成为优势类群;秋季调查中具槽帕拉藻(Paralia sulcata)成为优势类群。【结论】南麂列岛浮游植物群落在近二十年来物种数及丰度均发生了一定程度的变化:物种数大幅减少,春秋季平均丰度上升。

g【Objective】This article studied the current status of phytoplankton community struc-tures in Nanji Islands, Zhejiang Province and its relationships with environmental factors, to provide scientific support for assessment on the situation and development trend of the ecologi-cal environment quality of this marine area.【 Methods】 The species composition, density, domi-nance indices,the Shannon-Weiner diversity and the index of nutritional status assessment were analyzed based on the survey data of 28 stations in Nanji Islands in November, 2013 and May, 2014, respectively. [ResultslThe index of nutritional status assessment revealed that the majori-ty of the Nanji Islands sea area was in the condition of eutrophication. 24 phytoplankton species were identified in the spring and 22 species in the autumn with diatom and dinoflagellate domi-nated in both seasons. In the spring, Noctilucas cintillans ,Coscinodiscus sp. and Thalassiosira sp. were the dominant species, while Paralia sulcata dominated in the autumn .【 Conclusion】 The species composition of the phytoplankton in Nanji Islands sea area has decreased significantly and the average abundance has increased,in com-parison with the previous reports.